Gains from trade

Abstract

In a social choice context, we ask whether there exists a rule in which nobody loses under trade liberalization. We consider a resource allocation problem in which the traded commodities vary. We propose an axiom stating that enlarging the set of tradable commodities hurts nobody. We show that if a rule satisfies this axiom, together with an allocative efficiency axiom and an institutional constraint axiom stating that only preferences over tradable commodities matter, gains from trade can be given to only one individual in the first step of liberalization.